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MAX44250/MAX44251/MAX44252

20V, Ultra-Precision, Low-Noise Op Amps

General Description

The MAX44250/MAX44251/MAX44252 are 20V, ultra-

precision, low-noise, low-drift amplifiers that offer near-

zero DC offset and drift through the use of patented auto-

correlating zeroing techniques. This method constantly

measures and compensates the input offset, eliminating

drift over time and temperature and the effect of 1/f noise.

These single, dual, and quad devices feature rail-to-rail

outputs, operate from a single 2.7V to 20V supply or dual

±1.35V to ±10V supplies and consume only 1.15mA

per channel, while providing 5.9nV/√Hz input-referred

voltage noise. The ICs are unity-gain stable with a gain-

bandwidth product of 10MHz.

With excellent specifications such as offset voltage of

6µV (max), drift of 19nV/°C (max), and 123nV

P-P

noise in

0.1Hz to 10Hz, the ICs are ideally suited for applications

requiring ultra-low noise and DC precision such as inter-

facing with pressure sensors, strain gauges, precision

weight scales, and medical instrumentation.

The ICs are available in 5-pin SOT23, 8-pin SOT23,

8-pin µMAX

, and 14-pin SO packages and are rated

over the -40°C to +125°C temperature range.

Benefits and Features

S 2.7V to 20V Power-Supply Range

S Integrated EMI Filter

S 6µV Input Offset Voltage (max) at Room

Temperature

S TCV

of 19nV/°C (max)

S Low 5.9nV/√Hz Input-Referred Voltage Noise

S 123nV

P-P

in 0.1Hz to 10Hz

S Fast 400ns Settling Time

S 10MHz Gain-Bandwidth Product

S Rail-to-Rail Output

S High Accuracy Enables Precision Signal Chain

Acquisition

Applications

Strain Gauges

Pressure Transducers

Medical Instrumentation

Precision Instrumentation

Load Cell and Bridge Transducer Amplification

Typical Operating Circuit

19-6000; Rev 4; 6/14

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part,

refer to www.maximintegated.com/MAX44250.related.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Functional Diagrams appear at end of data sheet.

EVALUATION KIT AVAILABLE

10V

+10V

3.3V

MICRO-

PROCESSOR

OUT

50R

REF

IN-

IN+

BUFFER

MAX44251

MAX11211

MAX6126

MAX44251

+10V

1.5V

BUFFER

OUTPUT

-10V

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

Summary of content (14 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps General Description The MAX44250/MAX44251/MAX44252 are 20V, ultraprecision, low-noise, low-drift amplifiers that offer nearzero DC offset and drift through the use of patented autocorrelating zeroing techniques. This method constantly measures and compensates the input offset, eliminating drift over time and temperature and the effect of 1/f noise.
PAGE 2
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps ABSOLUTE MAXIMUM RATINGS Supply Voltage (VDD to VSS).................................-0.3V to +22V All Other Pins...................................(VSS - 0.3V) to (VDD + 0.3V) Short-Circuit Duration to Either Supply Rail............................. 1s Continuous Input Current (any pin).................................. ±20mA Differential Input Voltage.......................................................
PAGE 3
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps ELECTRICAL CHARACTERISTICS (continued) (VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps ELECTRICAL CHARACTERISTICS (VDD = 3.3V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX 1.17 1.65 UNITS POWER SUPPLY Quiescent Current Per Amplifier (MAX44250) IDD RL = J Quiescent Current Per Amplifier (MAX44251/MAX44252)) IDD RL = J Power-Up Time tON TA = +25NC -40NC < TA < +125NC 1.
PAGE 5
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps ELECTRICAL CHARACTERISTICS (continued) (VDD = 3.3V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS AC SPECIFICATIONS Input Voltage-Noise Density eN Input Voltage Noise Input Current-Noise Density Input Capacitance Gain-Bandwidth Product iN f = 1kHz 6.2 nV/√Hz 0.
PAGE 6
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10kI to VDD/2. TA = +25NC, unless otherwise specified.) INPUT OFFSET VOLTAGE vs. INPUT COMMON MODE 1.24 5 1.22 5 VOS (µV) 1.18 1.16 1.14 1.12 SUPPLY CURRENT PER AMPLIFIER 1.08 4 VOS (µV) 4 1.20 1.
PAGE 7
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10kI to VDD/2. TA = +25NC, unless otherwise specified.) 400 300 200 250 25 200 150 100 20 15 10 100 50 5 0 0 0 6 8 10 0 2 OUTPUT VOLTAGE SWING LOW vs. TEMPERATURE 12 10 8 6 4 2 -50 10 140 120 0 25 50 75 100 80 60 40 20 0 1 15 10 5 INPUT CURRENT NOISE vs.
PAGE 8
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10kI to VDD/2. TA = +25NC, unless otherwise specified.) SMALL-SIGNAL STEP RESPONSE vs. TIME LARGE-SIGNAL RESPONSE MAX44250 toc20 MAX44250 toc19 0 -5 MAX44250 toc21 AV = 1V/V VIN = 100mVP-P VOLTAGE (100mV/div) -10 -15 -20 -25 -30 -35 AV = 1V/V VIN = 2VP-P INPUT INPUT VOLTAGE (1V/div) 5 MAGNITUDE (dB) LARGE-SIGNAL STEP RESPONSE vs.
PAGE 9
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Pin Configurations TOP VIEW + OUTA 1 5 VDD MAX44250 VSS 2 INA+ 3 4 N.C. 1 INAINA+ 2 3 VSS 4 + 8 MAX44250 N.C. 7 VDD 6 OUTA 5 N.C.
PAGE 10
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Detailed Description The MAX44250/MAX44251/MAX44252 are high-precision amplifiers that have less than 3FV of typical inputreferred offset and low flicker noise. These characteristics are achieved through an autozeroing technique that samples and finds repeating patterns of signal to cancel the input offset voltage and 1/f noise of the amplifier.
PAGE 11
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps ADC Buffer Amplifier The MAX44250/MAX44251/MAX44252's low input offset voltage, low noise, and fast settling time make these amplifiers ideal for ADC buffers. Weigh scales are one application that often require a low-noise, high-voltage amplifier in front of an ADC. Figure 1 details an example of a load cell and amplifier driven from the same Q10V supplies, along with the MAX11211 18-bit delta sigma ADC.
PAGE 12
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Functional Diagrams TOP VIEW + + OUT 1 5 OUTA 1 VDD VSS 2 IN+ 3 4 IN- 8 VDD INA- 2 7 OUTB INA+ 3 6 INB- VSS 4 5 INB+ MAX44251 MAX44250 + OUTA + 1 14 OUTD 8 N.C. INA- 2 13 IND- 2 7 VDD INA+ 3 12 IND+ 3 6 OUT VDD 4 VSS 4 5 N.C. INB+ 5 10 INC+ INB- 6 9 INC- OUTB 7 8 OUTC N.C.
PAGE 13
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO.
PAGE 14
MAX44250/MAX44251/MAX44252 20V, Ultra-Precision, Low-Noise Op Amps Revision History REVISION NUMBER REVISION DATE 0 10/11 Initial release 1 12/11 Released the MAX44252 and updated the Typical Operating Characteristics. 2 8/12 Added the MAX44250 to the data sheet, added MAX44251 EMIRR graph to Typical Operating Characteristics, and revised Figure 2. 1–16 3 4/13 Updated General Description, Typical Operating Circuit, and Figure 1.